#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>

int main(int a = 1, int b = 2) {
	b = 2;
	printf("a=%d,b=%d",a,b);
	a = a ^ b;
	b = a ^ b;
	a = a ^ b;
	printf("a=%d,b=%d",a,b);
	return 0;
}